Field of the Invention
The present invention relates to an adjustment device for adjusting the position of at least one light module in a housing of a headlight, having a rotary member for at least indirectly transmitting a rotary motion to the at least one light module, wherein at least at one location, the rotary member is guided through an opening in the housing, and wherein for sealing the housing against the rotary member, an elastic sealing member is provided against an annular surface bordering the opening which bears against the housing.
Description of the Background Art
From DE 199 41 406 A1, which corresponds to U.S. Pat. No. 6,315,438, an adjustment device for adjusting the position of a light module in the housing of a headlight is known. The adjustment device comprises a rotary member which is guided at one location through an opening in the housing. In order to achieve a sealing of the opening in the housing, a sealing member is provided which bears against an annular surface of the housing, which surrounds the opening. Furthermore, the rotary member penetrating the opening has sealing lips which abut against the inside of the opening to achieve a further seal. Disadvantageously, the seal provided may result in the rotary motion of the rotary member in the housing being difficult to move, in particular when the lubricant employed ages or the rotary member is not moved for an extended period of time. In order to ensure adequate sealing of the housing, in particular to prevent the penetration of moisture but also of contamination, a contact pressure of the annular element against the annular surface on the housing must be provided. Due to the high contact pressure and the friction pairing of plastic to plastic, higher friction torques result, which additionally cause the rotary motion of the rotary member in the opening of the housing to move with difficulty.
From WO 2013/064164 A1, which corresponds to U.S. Pat. No. 9,381,850, which is herein incorporated by reference, a further adjustment device for adjusting the position of a light module in the housing of a headlight is known, wherein a rotary member is guided through an opening in the housing and is sealed by a sealing member. The sealing member is formed by a rubber ring which is pressed against the annular surface inside the housing, which borders the opening in the housing.
However, in the conventional art, in particular, when the materials age and plasticizers in the rubber-elastic material of the sealing member are no longer fully effective, the rotary motion of the rotary member in the housing may move with difficulty. This resistance can lead to failure of the adjustment device. On the other hand, a certain contact pressure must be present with which the sealing member is pressed against the annular surface on the housing to achieve reliable sealing of the housing interior against external moisture and contamination.